One small construction innovation could drastically reduce global carbon emissions.

Outside the realm of old-school mafia murder, cement doesn’t strike most people as dangerous. But it is.

The chemical process of making cement—a key ingredient in concrete—emits 8% of the world’s carbon dioxide. “If the cement industry were a country,” says BBC News, “it would be the third largest emitter in the world - behind China and the US.” That may mean the most toxic car you can think of—let’s say the black-exhaust-belching 1970s Dodge your granddad refuses to let go—is less deleterious to the environment than the street upon which it sputters.

In order to meet the requirements of the Paris Agreement on climate change, annual emission from cement needs to fall by at least 16% by 2030—an enormous undertaking. Concrete—low-cost, easily produced, and durable—has fashioned itself as the veritable backbone of city infrastructure, a go-to building material for most tower blocks, bridges, dams, and car parks. It’s the DNA for post-war buildings, ranging from the grimmest Soviet-style office building to gorgeous architectural wonders, such as the Sydney Opera House. Since 1950, production has increased, “more than thirtyfold… and almost fourfold since 1990.”

(Image via U.S. Air Force)

So what do we do? We could return to old materials, like sticks, bricks, and straw, but that’s costly, unrealistic, and better suited for Little Pigs. A much better solution: inventing a new kind of cement. A clean and green cement. A cement that doesn’t compete with private jets and cow belches for releasing the worst of our greenhouse gases.

Where could we find such a miracle?

Enter Ginger Krieg Dosier, co-founder and CEO of BioMason, a North Carolina-based startup that uses trillions of bacteria to grow bio-concrete bricks. A trained architect, Ms. Krieg Dosier look into finding green alternatives to bricks and masonry over 10 years ago, and was surprised at her dearth of options. This discovery, combined with her fascination with marine cements and structures, led her to create her own solution. She invented a technique which involves placing sand in moulds and injecting it with microorganisms—similar to the one that creates coral.

Despite the fact that certain writers would like to implement bio-bricks immediately, imagining a safer, climate-stabilized world (in which all office buildings resemble King Triton’s castle in The Little Mermaid), most architects, engineers, and contractors and clients are, unsurprisingly, more cautious. Still, Ms. Krieg Dosier says we have reason to be optimistic.

“I do believe the construction industry is approaching a point where alternative materials will be more widely adopted,” she says.

For the sake of our planet—and every living thing on it—let’s hope so.